Report Summary

Light products from asphaltenic oil residues

A new route in refinery technology has been investigated. This applies the removal of asphalt from heavy residues by solvent extraction, followed by flash coking of the asphaltenes obtained and hydrotreatment of the products. The project should provide an increased yield of gasoline and fuel oil.

The work programme began with the modification of a bench scale flash coking unit which simulates the LR coking process. Extended flash coking tests were performed with selected solid asphaltenes ranging between 40 and 53 weight in Conradson carbon content. The results revealed a correlation of oil yield with flash coking temperature and heat carrier recycle ratio. The lowest possible coking temperature and recycle ratio were found to be preferable. The LR flash coking obtained was subjected to fractionation into naphtha, gas oil and vacuum gas oil distillate cuts. Inspection of products and subsequent hydrotreatment of coker distillates blended with corresponding SR oil products revealed a great potential for this novel upgrading route for heavy residues.

These results have been confirmed by a conceptual technical and commercial study of this route applied to a million tonnes per year refinery for cold lake bitumen.